WO2020196002A1

WO2020196002A1 - Scroll compressor

Info

Publication number: WO2020196002A1
Application number: PCT/JP2020/011352
Authority: WO
Inventors: 今井　哲也; 泰造佐藤
Original assignee: サンデン・オートモーティブコンポーネント株式会社
Priority date: 2019-03-22
Filing date: 2020-03-16
Publication date: 2020-10-01
Also published as: US11867173B2; JP2020153339A; CN113631816B; CN113631816A; DE112020001389T5; US20220136500A1; JP7280727B2

Abstract

[Problem] To provide a scroll compressor with which it is possible for a pressure loss in a pathway extending from a discharge space to a discharge port to be reduced effectively. [Solution] This scroll compressor is provided with a discharge space 27 formed in a compressing mechanism cover 9 of a housing 11, a discharge hole 26 which is formed in a fixed scroll 21 and which discharges compressed refrigerant into the discharge space, a discharge port 51 for discharging the refrigerant to the outside of the housing, a relief passage 71 providing communication between the discharge space and the discharge port, and a differential pressure valve 74 which is provided in the relief passage and which opens in accordance with a pressure difference between the discharge space and the discharge port, wherein the relief passage opens in the discharge space above the discharge hole.

Description

Scroll compressor

The present invention relates to a scroll compressor that compresses a working fluid in a compression chamber formed between laps of both scrolls by revolving a movable scroll with respect to a fixed scroll.

Conventionally, this type of scroll compressor has a compression mechanism consisting of a fixed scroll having a spiral wrap on the surface of the end plate and a movable scroll having a spiral wrap on the surface of the end plate, and the laps of each scroll are opposed to each other. A compression chamber is formed between the laps, and the movable scroll is revolved around the fixed scroll to compress the working fluid (refrigerant) in the compression chamber (see, for example, Patent Document 1). ).

Further, in Patent Document 1, a relief passage connecting the discharge space (the discharge chamber of Document 1) and the discharge passage is formed, and a relief valve that opens the valve by a differential pressure is provided in this relief passage. Further, the relief passage is opened in the discharge space (discharge chamber) below the discharge hole (discharge port in the literature), and the liquid accumulated in the discharge space (discharge chamber) is discharged to the discharge passage.

JP-A-2010-151060

Here, in this type of scroll compressor, a muffler chamber for reducing pulsation and an oil separator described in Patent Document 1 are arranged between a normal discharge space and a discharge port. Then, the working fluid discharged from the discharge hole of the fixed scroll into the discharge space reaches the discharge port after passing through these oil separators and muffler chambers.

Therefore, there is a problem that pressure loss occurs due to passing through the oil separator and the muffler chamber, and the efficiency is lowered, especially under the high volume flow rate condition of the working fluid (discharge gas) discharged from the discharge hole. Regarding this point, since the above-mentioned Patent Document 1 has a structure in which the relief passage is opened below the discharge hole and the liquid accumulated in the discharge space is discharged to the discharge passage, the above-mentioned effect of reducing the pressure loss is expected. Can not.

The present invention has been made to solve such conventional technical problems, and to provide a scroll compressor capable of effectively reducing a pressure loss in a path from a discharge space to a discharge port. The purpose.

The scroll compressor of the present invention is provided in a housing with a compression mechanism consisting of a fixed scroll and a movable scroll in which spiral wraps are formed so as to face each other on each surface of each end plate, and the movable scroll revolves with respect to the fixed scroll. By rotating the scroll, the working fluid is compressed in the compression chamber formed between the laps of both scrolls, and the discharge space formed in the housing and the working fluid formed and compressed in the fixed scroll. A discharge hole for discharging the working fluid to the discharge space, a discharge port for discharging the working fluid to the outside of the housing, a relief passage for communicating the discharge space and the discharge port, and a relief passage provided in the relief passage to reduce the pressure difference between the discharge space and the discharge port A differential pressure valve that opens accordingly is provided, and the relief passage is characterized by opening into the discharge space above the discharge hole.

The scroll compressor according to the second aspect of the present invention includes a muffler chamber located between the discharge space and the discharge port and formed in a housing so as to communicate with the discharge space, and the relief passage passes through the muffler chamber. It is characterized in that the discharge space and the discharge port are communicated with each other without any problem.

The scroll compressor according to the third aspect of the present invention includes the oil separator configured in the discharge space in the above invention, and the working fluid discharged from the discharge hole flows into the muffler chamber after passing through the oil separator and also has a relief passage. Is characterized in that the discharge space and the discharge port are communicated with each other without passing through the oil separator and the muffler chamber.

The scroll compressor according to the invention of claim 4 includes an oil separator configured in the discharge space according to the invention of claim 2, and the working fluid discharged from the discharge hole flows into the muffler chamber after passing through the oil separator. The relief passage is characterized in that the working fluid outlet of the oil separator and the discharge port are communicated with each other without passing through the muffler chamber.

The scroll compressor according to claim 5 is characterized in that, in each of the above inventions, the differential pressure valve opens when the pressure in the discharge space becomes higher than the pressure in the discharge port and the difference between them reaches a predetermined value PD1. ..

The scroll compressor of the invention of claim 6 is provided in the discharge hole in the above invention, and includes a discharge valve that opens when the differential pressure between the compression chamber and the discharge space reaches a predetermined value PD2, and the predetermined value PD1 is a predetermined value PD2. It is characterized by being larger.

According to the present invention, a relief passage is formed in which a discharge space for discharging the working fluid from the discharge hole of the fixed scroll and a discharge port for discharging the working fluid to the outside of the housing are communicated with each other, and the discharge space and the discharge port are formed in this relief passage. Since a differential pressure valve that opens according to the differential pressure is provided and the relief passage is opened in the discharge space above the discharge hole, the discharge space is as described in claims 2 to 4 under the high volume flow rate condition of the working fluid. It becomes possible to effectively reduce the pressure loss in the muffler chamber provided between the and the discharge port and the oil separator formed in the discharge space, and improve the efficiency.

In addition, since the degree of freedom in designing the muffler chamber is increased, the discharge pulsation under low speed conditions can be effectively reduced. Further, by setting the condition for opening the differential pressure valve as in claim 5 and 6, the pressure loss can be smoothly reduced.

It is sectional drawing of the scroll compressor of one Embodiment to which this invention was applied. It is a front view of the compression mechanism cover of the scroll compressor of FIG. It is a figure explaining the flow of the refrigerant (working fluid) from the compression mechanism of the scroll compressor of FIG. 1 to the refrigerant circuit.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of a scroll compressor 1 of an embodiment to which the present invention is applied. The scroll compressor 1 of this embodiment is used, for example, in the refrigerant circuit R (FIG. 3) of the vehicle air conditioner, and sucks, compresses, and discharges the refrigerant as the working fluid of the vehicle air conditioner. This is a so-called inverter-integrated scroll compressor including an electric motor 2, an inverter 3 for operating the electric motor 2, and a compression mechanism 4 driven by the electric motor 2.

The scroll compressor 1 of the embodiment includes a main housing 6 that houses an electric motor 2 and an inverter 3 inside, a compression mechanism housing 7 that houses a compression mechanism 4 inside, an inverter cover 8, and a compression mechanism cover 9. It has. The main housing 6, the compression mechanism housing 7, the inverter cover 8, and the compression mechanism cover 9 are all made of metal (made of aluminum in the embodiment), and they are integrally joined to the scroll compressor 1. Housing 11 is configured. That is, the compression mechanism cover 9 constitutes a part of the housing 11.

The main housing 6 is composed of a tubular peripheral wall portion 6A and a partition wall portion 6B. The partition wall portion 6B is a partition wall that partitions the inside of the main housing 6 into a motor accommodating portion 12 accommodating the electric motor 2 and an inverter accommodating portion 13 accommodating the inverter 3. One end surface of the inverter accommodating portion 13 is open, and this opening is closed by the inverter cover 8 after the inverter 3 is accommodated.

The other end surface of the motor accommodating portion 12 is also open, and this opening is closed by the compression mechanism housing 7 after the electric motor 2 is accommodated. The partition wall portion 6B is provided with a support portion 16 for supporting one end portion (the end portion on the opposite side of the compression mechanism 4) of the rotating shaft 14 of the electric motor 2.

The compression mechanism housing 7 has an opening on the side opposite to the main housing 6, and this opening is closed by the compression mechanism cover 9 after the compression mechanism 4 is accommodated. The compression mechanism housing 7 is composed of a tubular peripheral wall portion 7A and a frame portion 7B on one end side (main housing 6 side) thereof, and the compression mechanism 4 is contained in a space partitioned by the peripheral wall portion 7A and the frame portion 7B. Is housed. The frame portion 7B forms a partition wall that separates the inside of the main housing 6 from the inside of the compression mechanism housing 7.

Further, the frame portion 7B is provided with a through hole 17 through which the other end of the rotating shaft 14 of the electric motor 2 (the end on the compression mechanism 4 side) is inserted, and the through hole 17 is provided on the compression mechanism 4 side. A front bearing 18 as a bearing member that supports the other end of the rotating shaft 14 is fitted. Reference numeral 19 denotes a sealing material that seals the outer peripheral surface of the rotating shaft 14 and the inside of the compression mechanism housing 7 at the through hole 17.

The electric motor 2 is composed of a stator 25 around which a coil 35 is wound and a rotor 30. Then, for example, the direct current from the vehicle battery (not shown) is converted into a three-phase alternating current by the inverter 3 and supplied to the coil 35 of the electric motor 2, so that the rotor 30 is rotationally driven. ing.

Further, a suction port (not shown) is formed in the main housing 6, and after the refrigerant sucked from the suction port passes through the main housing 6, the outside of the compression mechanism 4 in the compression mechanism housing 7 will be described later. It is sucked into the suction unit 37. As a result, the electric motor 2 is cooled by the intake refrigerant. Further, the refrigerant compressed by the compression mechanism 4 is discharged into the discharge space 27 as described later, and then finally outside the housing 11 from the discharge port 51 formed in the compression mechanism cover 9, that is, the refrigerant circuit R. It is configured to be discharged to.

The compression mechanism 4 is composed of a fixed scroll 21 and a movable scroll 22. The fixed scroll 21 integrally includes a disk-shaped end plate 23 and an involute-shaped or spiral wrap 24 having a curved line similar thereto standing on the surface (one surface) of the end plate 23. The surface of the end plate 23 on which the wrap 24 is erected is fixed to the compression mechanism housing 7 with the frame portion 7B side as the side. A discharge hole 26 is formed in the center of the end plate 23 of the fixed scroll 21, and the discharge hole 26 communicates with the discharge space 27 in the compression mechanism cover 9. Reference numeral 28 denotes a discharge valve provided in the opening on the back surface (the other surface) side of the end plate 23 of the discharge hole 26. The discharge valve 28 opens when the pressure in the compression chamber 34 becomes higher than the pressure in the discharge space 27 and their differential pressure reaches a predetermined value PD2, and communicates the discharge hole 26 with the discharge space 27.

The movable scroll 22 is a scroll that revolves and turns with respect to the fixed scroll 21, and is a disk-shaped end plate 31 and an involute shape erected on the surface (one surface) of the end plate 31 or an approximation thereof. A spiral wrap 32 made of a curved line and a boss portion 33 protruding from the center of the back surface (the other surface) of the end plate 31 are integrally provided. The movable scroll 22 is arranged so that the lap 32 faces the lap 24 of the fixed scroll 21 and meshes with each other with the protruding direction of the lap 32 as the fixed scroll 21 side, and the compression chamber 34 is provided between the

laps

24 and 32. To form.

That is, the lap 32 of the movable scroll 22 faces the lap 24 of the fixed scroll 21, and the tip of the lap 32 is in contact with the surface of the end plate 23, and the tip of the lap 24 is in contact with the surface of the end plate 31. The other end of the rotating shaft 14, that is, the end on the movable scroll 22 side, is provided with a drive protrusion 48 that protrudes at a position eccentric from the axis of the rotating shaft 14. An eccentric bush 36 is attached to the drive projection 48, and is provided at the other end of the rotating shaft 14 eccentrically from the axial center of the rotating shaft 14.

In this case, the eccentric bush 36 is attached to the drive projection 48 at a position eccentric from the axial center of the eccentric bush 36, and the eccentric bush 36 is fitted to the boss portion 33 of the movable scroll 22. Then, when the rotating shaft 14 is rotated together with the rotor 30 of the electric motor 2, the movable scroll 22 is configured to revolve and rotate with respect to the fixed scroll 21 without rotating. Reference numeral 49 denotes a balance weight attached to the outer peripheral surface of the rotating shaft 14 on the movable scroll 22 side of the front bearing 18.

Since the movable scroll 22 revolves eccentrically with respect to the fixed scroll 21, the eccentric direction and the contact position of each of the

laps

24 and 32 move while rotating, and the compression chamber 34 sucking the refrigerant from the above-mentioned suction portion 37 on the outside. Gradually shrinks while moving inward. As a result, the refrigerant is compressed and finally discharged from the central discharge hole 26 to the discharge space 27 via the discharge valve 28.

In FIG. 1, 38 is an annular thrust plate. The thrust plate 38 is for partitioning the back pressure chamber 39 formed on the back surface side of the end plate 31 of the movable scroll 22 and the suction portion 37 as the suction pressure region outside the compression mechanism 4 in the compression mechanism housing 7. It is located outside the boss portion 33 and is interposed between the frame portion 7B and the movable scroll 22. Reference numeral 41 denotes a sealing material attached to the back surface of the end plate 31 of the movable scroll 22 and abutting against the thrust plate 38, and the back pressure chamber 39 and the suction portion 37 are partitioned by the sealing material 41 and the thrust plate 38.

Note that 42 is a sealing material that is attached to the surface of the frame portion 7B on the thrust plate 38 side, abuts on the outer peripheral portion of the thrust plate 38, and seals between the frame portion 7B and the thrust plate 38.

Further, in FIG. 1, reference numeral 43 denotes a back pressure passage formed from the compression mechanism cover 9 to the compression mechanism housing 7, and an orifice 44 is installed in the back pressure passage 43. The back pressure passage 43 communicates the oil outlet 53A of the oil separator 52 configured in the discharge space 27 of the compression mechanism cover 9 with the back pressure chamber 39, whereby the back pressure chamber is as shown by an arrow in FIG. The 39 is configured to be supplied with oil having a discharge pressure adjusted by reducing the pressure at the orifice 44.

The pressure (back pressure) in the back pressure chamber 39 causes a back pressure load that presses the movable scroll 22 against the fixed scroll 21. Due to this back pressure load, the movable scroll 22 is pressed against the fixed scroll 21 against the compression reaction force from the compression chamber 34 of the compression mechanism 4, and the contact between the

laps

24 and 32 and the

end plates

31 and 23 is maintained and compressed. The refrigerant can be compressed in the chamber 34.

On the other hand, an oil passage 46 extending in the axial direction is formed in the rotating shaft 14, and a pressure adjusting valve 47 is provided in the oil passage 46 located on the support portion 16 side. The oil passage 46 communicates the back pressure chamber 39 with the inside of the main housing 6 (suction pressure region), and the oil flowing into the back pressure chamber 39 from the back pressure passage 43 flows into the oil passage 46 and is the main. Although it flows out into the housing 6, the pressure regulating valve 47 opens when the pressure (back pressure) in the back pressure chamber 39 reaches the maximum value, and functions so that the back pressure does not rise any more.

Next, the detailed structure of the above-mentioned compression mechanism cover 9 that constitutes a part of the housing 11 will be described with reference to FIGS. 1 and 2. As described above, the oil separator 52 is configured in the discharge space 27. The oil separator 52 is integrally formed with the compression mechanism cover 9, and has an oil separation portion 54 having an oil separation space 53 inside, and an upper portion of the oil separation space 53 inserted into the oil separation portion 54 from above. The lower end refrigerant outlet (working fluid outlet) 56A is formed so as to face the side surface of the oil separation cylinder 56 and the oil separation cylinder 56 opened in the oil separation space 53, other than the oil separator 52. It is composed of two

communication holes

57 and 57 that communicate the discharge space 27 and the oil separation space 53, and the lower end of the oil separation space 53 is the oil outlet 53A described above.

Further, in the compression mechanism cover 9, a plurality of

muffler chambers

61, 62, 63 and a discharge port chamber 64 are configured around the discharge space 27, and the muffler chamber 61 and the muffler chamber 62 are throttled. The muffler chamber 62 and the muffler chamber 63 are communicated by the throttle portion 67, the muffler chamber 63 and the discharge port chamber 64 are communicated by the throttle portion 68, and the first muffler chamber 61 and the oil separator are communicated with each other. The upper part of the oil separation cylinder 56 of 52 is communicated with the communication passage 69. Further, the discharge port chamber 64 is communicated with the discharge port 51 to form a part of the discharge port 51.

Further, in the present invention, a relief passage 71 is formed in the compression mechanism cover 9, and a differential pressure valve 74 composed of a ball valve 72 and a compression spring 73 is provided in the relief passage 71. One end of the relief passage 71 opens to the discharge space 27 above the discharge hole 26 of the fixed scroll 21, and the other end opens to the discharge port chamber 64, whereby the discharge space 27 and the discharge port chamber 64 (discharge port). It communicates with 51). In addition, what is shown by P1 in FIG. 2 is the position of the discharge hole 26 of FIG.

Further, the compression spring 73 of the differential pressure valve 74 always presses the ball valve 72 against the valve seat (formed in the relief passage 71) to close the relief passage 71 (the differential pressure valve 74 is closed), but the discharge space. When the pressure of 27 becomes higher than the pressure of the discharge port chamber 64 (discharge port 51) and their differential pressure reaches a predetermined value PD1, the ball valve 72 separates from the valve seat against the spring force of the compression spring 73. The relief passage 71 is opened (the differential pressure valve 74 is opened).

Here, the predetermined value PD1 of the differential pressure that the differential pressure valve 74 opens is larger than the predetermined value PD2 of the differential pressure between the compression chamber 34 and the discharge space 27 that the discharge valve 28 opens, and the spring force of the compression spring 73. Is set.

With the above configuration, the flow of the refrigerant from the compression mechanism 4 to the refrigerant circuit R will be described next with reference to FIG. When the refrigerant is compressed by the rotation of the movable scroll 22 with respect to the fixed scroll 21 as described above and the differential pressure between the compression chamber 34 and the discharge space 27 reaches the predetermined value PD2, the discharge valve 28 opens and the refrigerant is discharged from the discharge hole 26. It is discharged to 27. It is assumed that the differential pressure valve 74 is closed under a normal operating state in which the volumetric flow rate of the refrigerant (discharged gas) is relatively low.

The refrigerant (including oil) that has flowed into the discharge space 27 in this way flows into the oil separation space 53 of the oil separator 52 from the communication holes 57 and 57, and swirls around the oil separation cylinder 56. The oil in the refrigerant is separated by the centrifugal force at this time, and the separated oil is supplied from the oil outlet 53A to the back pressure chamber 39 as described above via the back pressure passage 43 and the orifice 44.

On the other hand, the refrigerant from which the oil has been separated flows into the oil separation cylinder 56 from the refrigerant outlet 56A, and flows into the muffler chamber 61 via the communication passage 69. Then, the refrigerant circuit R flows into the discharge port chamber 64 in sequence through the throttle portion 66, the muffler chamber 62, the throttle portion 67, the muffler chamber 63, and the throttle portion 68, and finally from the discharge port 51 to the outside of the housing 11. (Flow on the upper side of FIG. 3).

The amount of oil flowing out to the refrigerant circuit R is suppressed by the oil separator 52, and the pulsation of the refrigerant discharged to the refrigerant circuit R by the muffler chambers 61 to 63 and the throttle portions 66 to 68 is reduced. Under the high volume flow rate condition of the refrigerant (discharged gas) discharged from the hole 26, pressure loss occurs by passing through the oil separator 52 and the muffler chambers 61 to 63, and the efficiency is lowered.

Therefore, in the present invention, the relief passage 71 and the differential pressure valve 74 described above are provided. That is, the pressure loss becomes large under the high volume flow rate condition as described above, the pressure in the discharge space 27 rises more than the pressure in the discharge port chamber 64 (discharge port 51), and the differential pressure between them becomes the predetermined value described above. When it reaches PD1, the differential pressure valve 74 opens to open the relief passage 71, and the discharge space 27 and the discharge port chamber 64 (discharge port 51) do not pass through the oil separator 52 and the muffler chambers 61 to 63. That is, they are bypassed and communicated.

As a result, the refrigerant in the discharge space 27 bypasses the oil separator 52 and the muffler chambers 61 to 63 and flows into the discharge port chamber 64 (discharge port 51). The pressure loss in the 52 and the muffler chambers 61 to 63 is effectively reduced, and the efficiency is improved. Further, since the degree of freedom in designing the muffler chambers 61 to 63 is increased, the discharge pulsation under low speed conditions can be effectively reduced. Further, in the embodiment, the above-mentioned predetermined value PD1 in which the differential pressure valve 74 opens is made larger than the above-mentioned predetermined value PD2 in which the discharge valve 28 opens, so that the pressure loss can be smoothly reduced.

In the above embodiment, the discharge space 27 and the discharge port chamber 64 (discharge port 51) are communicated with each other by the relief passage 71 provided with the differential pressure valve 74, but the present invention is not limited to this, and is shown by a broken line in FIG. As described above, the refrigerant outlet (working fluid outlet) 56A or the communication passage 69 of the oil separation cylinder 56 from which the refrigerant flows out from the oil separator 52 and the discharge port chamber 64 (discharge port 51) are communicated with each other by the relief passage 71. It may be.

As a result, the refrigerant in the discharge space 27 bypasses the muffler chambers 61 to 63 and flows into the discharge port chamber 64 (discharge port 51), so that the muffler chambers 61 to 63 The pressure loss in is effectively reduced.

In the embodiment, the present invention is applied to the scroll compressor used in the refrigerant circuit of the air conditioner for vehicles, but the present invention is not limited to this, and the present invention is effective for the scroll compressor used in the refrigerant circuit of various refrigerating devices. Is. Further, in the embodiment, the present invention is applied to a so-called inverter-integrated scroll compressor, but the present invention is not limited to this, and the present invention can also be applied to a normal scroll compressor not integrally provided with an inverter.

1 Scroll compressor 4 Compression mechanism 6 Main housing (part of housing 11)
7 Compression mechanism housing (part of housing 11)
9 Compression mechanism cover (part of housing 11)
11 Housing 21 Fixed scroll 22

Movable scroll

23, 31

End plate

24, 32 Wrap 26 Discharge hole 27 Discharge space 28 Discharge valve 34 Compression chamber 51 Discharge port 52 Oil separator 61-63 Muffler chamber 64 Discharge port chamber (part of discharge port)
69 Continuous passage 71 Relief passage 74 Differential pressure valve

Claims

A compression mechanism consisting of a fixed scroll and a movable scroll formed with spiral wraps facing each other on each surface of each end plate is provided in the housing, and the movable scroll is revolved and swirled with respect to the fixed scroll. In a scroll compressor that compresses the working fluid in a compression chamber formed between the laps of both scrolls.
The discharge space formed in the housing and
A discharge hole formed in the fixed scroll and discharging the compressed working fluid into the discharge space,
A discharge port that discharges the working fluid to the outside of the housing,
A relief passage that communicates the discharge space with the discharge port,
A differential pressure valve provided in the relief passage and opened according to the differential pressure between the discharge space and the discharge port is provided.
A scroll compressor characterized in that the relief passage opens into the discharge space above the discharge hole.
A muffler chamber located between the discharge space and the discharge port and formed in the housing so as to communicate with the discharge space is provided.
The scroll compressor according to claim 1, wherein the relief passage communicates between the discharge space and the discharge port without passing through the muffler chamber.
An oil separator configured in the discharge space is provided.
The working fluid discharged from the discharge hole flows into the muffler chamber after passing through the oil separator, and also
The scroll compressor according to claim 2, wherein the relief passage communicates between the discharge space and the discharge port without passing through the oil separator and the muffler chamber.
An oil separator configured in the discharge space is provided.
The working fluid discharged from the discharge hole flows into the muffler chamber after passing through the oil separator, and also
The scroll compressor according to claim 2, wherein the relief passage communicates with the working fluid outlet of the oil separator and the discharge port without passing through the muffler chamber.
The differential pressure valve is any one of claims 1 to 4, wherein the differential pressure valve opens when the pressure in the discharge space becomes higher than the pressure in the discharge port and the difference between them reaches a predetermined value PD1. Scroll compressor described in.
A discharge valve provided in the discharge hole and opened when the differential pressure between the compression chamber and the discharge space reaches a predetermined value PD2 is provided.
The scroll compressor according to claim 5, wherein the predetermined value PD1 is larger than the predetermined value PD2.